Conventionally, an electric device to/from which a battery pack is attached/detached and the battery pack configured to be attachable/detachable to/from the electric device have been known, and examples of the electric device and the battery pack are described in Patent Literature 1. An electric device described in Patent Literature 1 includes: a hollow tool main body; a hammer case fixed to an open end of the tool main body; and a grip provided continuously from the tool main body. Also, a preferred aim of the electric device described in Patent Literature 1 is to ensure a sealing property, and Patent Literature 1 describes providing elastic rubber at an insertion port for the battery pack in the grip by a double-layered molding process.